1. Field of the Invention
The present invention relates to a voltage applying apparatus suitable for manufacturing an electron source, and an apparatus and a method for manufacturing an electron source.
2. Description of Related Art
Conventionally, as electron-emitting devices, if they are roughly classified, two kinds of them, namely one is a thermion-emitting device and the other is a cold cathode electron-emitting device, are known. The cold cathode electron-emitting device includes a field emission type device, a metal/insulator-layer/metal type device, a surface conduction electron-emitting device and the like.
The surface conduction electron-emitting device utilizes the phenomenon of the occurrence of electron emission caused by an electric current flowing in parallel with a film surface of a small area thin film formed on a substrate. The basic structure, a manufacturing method and the like of the surface conduction electron-emitting device are disclosed in, for example, Japanese Patent Application Laid-Open Nos. 7-235255, 8-171849 and so forth.
The surface conduction electron-emitting device is characterized by a pair of opposed device electrodes and an electroconductive film which are formed on a substrate. The electroconductive film is connected with the pair of the device electrodes, and has an electron-emitting region in a part thereof. A fissure is formed in a part of the electroconductive film.
Moreover, a deposited film having at least either of carbon and a carbon compound as the main component thereof is formed at an end of the fissure.
By arranging a plurality of such electron-emitting devices on the substrate and by connecting each electron-emitting device to each other with wiring, an electron source equipped with a plurality of surface conduction electron-emitting devices can be made.
Moreover, by combining the electron source and a phosphor, a display panel of an image-forming apparatus can be formed.
Conventionally, the manufacturing of such a panel of an electron source has been performed as follows.
That is, as a first manufacturing method, first, an electron source substrate is made. The electron source substrate includes a plurality of devices and wiring connecting the plurality of devices to each other. The plurality of devices and the wiring are formed on the electron source substrate, and the plurality of devices is composed of an electroconductive film and a pair of device electrodes connected with the electroconductive film. Next, the whole of the made electron source substrate is placed in a vacuum chamber. Next, after exhausting the vacuum chamber, a “forming process” is performed by connecting a probe to external terminals (each of the terminals is a part of the wirings disposed on the substrate) and then applying a voltage to the pair of device electrodes through the probe for forming a fissure in the electroconductive film of each of the devices. Moreover, an “activation process” is performed in which a gas containing an organic material is introduced into the vacuum chamber and a voltage is again applied to each of the device electrodes through the probe, as discorsed at “forming process”, in an atmosphere containing an organic material to deposit carbon or a carbon compound in the vicinity of the fissure.
Moreover, as a second manufacturing method, first, an electron source substrate is made. The electron source substrate includes a plurality of devices and wiring connecting the plurality of devices to each other. The plurality of devices and the wiring are formed on the electron source substrate, and the plurality of devices is composed of an electroconductive film and a pair of device electrodes connected with the electroconductive film. Next, a panel of an image-forming apparatus is made by joining the made electron source substrate and a substrate on which a phosphor is arranged with a supporting frame put between the electron source substrate and the latter substrate. After that, a “forming process” is performed by firstly exhausting inside the panel through a pipe attached to the panel and secondly connecting a probe to external terminals (each of the terminals is a part of the wirings disposed on the substrate) and then applying a voltage to the pair of device electrodes through the probe for forming a fissure in the electroconductive film of each of the devices. Moreover, an “activation process” is performed in which a gas containing an organic material is introduced into the panel through the exhaust pipe and a voltage is again applied to each of the devices through the probe, as discorsed at “forming process”, in an atmosphere containing an organic material to deposit carbon or a carbon compound in the vicinity of the fissure.